Nozzle



July 24, 1951 L. T. HERRMANN NOZZLE Filed June 23, 1947 ill.,

INVENTR. QU/5 7l' HERRMANN ATTORNEYS Patented July 24, 1951 NozzLE l v.,Louis.T. Herrmann, Pasadena, Calif. VApplication June 23, 1947, serial No'. 756,436

This inventionl is concerned with aspirator nozzles and provides anlimproved nozzle having highv aspirator -eiiiciency, tothe end thatamain stream ofiluid-will suck in aside streamwith but little diminution Vin -the force with which `the stream isejectedI as compared :with-*the force when-nothingisbeingsucked'in.l The aspirator nozzle of the 'invention' :is particularly n adapted VIor'tree-spraying and thellike where a powerful stream of long range is required. However;l it has @variety of applications. `Thus it rnaylbel used to suck insecticide intov a stream of water;l tosuck fuel oil into a stream of-air, or to suck dust into a iluid stream, for example,v Apowdered insecticide employed in plant dusting. Thelaspirator ofthe invention is simple and rugged in its construction and forms a long range ljet more-efciently than manyfprior apparatus.

*ft has been proposedkheretofore to use-an aspirator nozzle providedwith-a restricted throat section and a side leg, the' two of which form an eductor. Suction-produced by a high velocity fluid stream-inthe restricted throat sucks in a side; stream which'mixes with `the-main stream asit passes through theeductor.- ffHowever, here`- tofore customaryl nozzles: incorporating such eductors have been relatively inefficient so that there has been marked: diminution of the flow of the nozzle when ysubstantial proportions ofr materialaresucked in through the side leg. r-As-aresult of my investigations'l have discovered thatY it is possible to so shapefand proportion as `aspirator ynozzle `provided with an eductor that markedincrease in the suction eciency is obtained withl little or no decrease in the throwv of the nozzle,v i. e.in.the range of the jet produced, even when a substantial amount of material (preferably fluid) .is being sucked in through' the side leg.

My invention ycontr-nnplates an. aspirating nozzle having a throatportionv offzelatively small cross section. This throatisenlargedabruptly into a concentric., chamber. `having ysu,bstantially parallel side walls.A Thus the-*chamber may: be of cylindrical form and concentricv with the throat. The width of the chamber should be 4.0% to 12.5% greater than the Width of the-throat at the point where it enters the ,4 chamber Aand the length of the Qhambeeshouldbefromgaoz times its Width. An aspiratingfconduit is connected to the chamber; preferably. immediately .ahead of the'xpoint at which v the :throat v:isV abruptly eX-v naxided*intoI thei chamber.' :alli-have. ounjd vthat a nozzlev eductorifproportonedxas ,deserihedaabove isextremely. eiiicient and; that substantial aspiral1.Glatillls. (Cl. 299-127) tion does not decrease perceptibly they rangevof the jet projected therefrom.

Preferably the chamber 'into'which the laspirator conduit or `side lleg enters is'followed by a secondY or mixingchamber. The mixing chamber is'concentric kwith the 4iirst chamber..y and fthe first expands abruptlyzinto the` mixing chamber, for example'by entering arwall'running transverse to the axis of the nozzle. The mixing chamber should vbeabout twicefas'wideastherst chamber and about as `long as it is wide." Thus it may be o'f cylindrical form, the diameter ofthe cylinder approximating its fdepth.

The main passagefor fluid -through the lnozzle (i. e. through the throat,thegrstzchamber'and the second chamberlypreferably continuesfin a flared end piece. This .end piece for most efficient throw and breakup of' a jet yshouldbe oval or elliptical in "cross sectionatifleast toward lits-outside end.

VIn order` to .break up thefstream issuing :from the first chamber into thev mixing chamber itis desirable toprovde a disperser member-'having a fiat end which makes anangle ranging from 15? to 25 with the axis of theapparatusi. e. theaxis of the throat andthe chambers. In other words; the angle between the axis of the stream asl-it approaches the flatdisperser surfaceuand the surface itself; measured in-a plane perpendicular-'to the surface is-180.-minus 15 to 251or 165 to 155. This flat disperser f surfaceV should -be adjustable with respect tothe depth vrthat ,it may be inserted into the issuing-jet. This is.done conveniently by forming it on. vthe. inside end of a screw threadedthroughthe sideof thev nozzle, vand providing an adjusting .knob :or handleon theouter end ofthescrew. y n

Further dispersion of this .jetinto ner drops may be obtained by sucking air into the chamber preferablythrough v a. ring of side ports which pass through-the :wall-of thernozzleran slopeslightlybackwards and outward.

For use in treevspra-ying and the like the throat of the,V nozzle .of the. :invention should loe` along frustc conical section ,taperinginthe direction` of flow, soas .toincreasethe velocity lof theWa-ter, passing through the throat :into-the rst chamber. For example, the throat may be asection at least.

6 Vinches longk tapering from 4an inside; ,diameter 0f, about .5/8 of 1 an inch .to an insideYd-iameter-Aof 5% of an inchin this length. l

For use as a fuel oil burner or thelike-with highpressure airv passing tl-rrouglrl ther main channel of the eductor, and witha-liquid being vsucked-.ia from theeside oraspiratorleg,` the longtapering.

throat may be omitted and instead a short throat employed. This short throat connects directly with a pipe of much larger diameter.

Increased suction can be obtained in the apparatus, although not without substantial reduction in throw of the stream, by placing another step in the throat ahead of the rst chamber. Such step takes the form of a smaller throat expanded abruptly into a parallel sided chamber ahead of that into which the side leg enters.

'Ihese and other aspects of the invention will be apparent in the light of the following detailed description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a longitudinal section through a preferred form of my aspirating nozzle particularly adapted for use in tree spraying and the like;

` Fig. 2 is a front View of the apparatus of Fig. 1;

Fig. 3 is a longitudinal section through another form of the aspirating nozzle of my invention particularly designed as a fuel oil burner; and

Fig. 4 illustrates a modification of the structure.'

l Referring to Figs. 1 and 2, the tree spraying nozzle aspirator comprises a long frusto conical throat portion I tapering in the direction of uid passage and preferably circular in interior cross section. The rear end of the throat portion has an enlarged female threaded section Il adapted to take standard male hose or pipe fittings. Although the degree of taper is not critical it should be roughly comparable to that obtaining when a conduit of circular cross section is tapered from 5A; inch diameter to about {i6- inch'diameter in a total length of about 6 inches.

The small end of the throat opens abruptly into a first coaxial cylindrical chamber l2, i. e. the end wall of the chamber makes approximately a right angle with the axis of the throat. This chamber is from 4.0 to 12.5% wider than the throat at the point where it enters the chamber. I have found that this proportion coupled with the length of the chamber is relatively critical in assuring maximum eiiciency of suction. Thus the chamber I2 should be from 2.8 to 5.2 times as long as it is wide, the optimum proportion being about 4.

A suction leg I3 enters the first chamber transversely to its axis immediately adjacent the point at which the throat enters the chamber. The cross section of this suction leg or conduit is not critical with respect to dimension. However, it should not be made too large. For an apparatus having a throat constricted to a diameter of of an inch at its small end a suction pipe made of 1A; inch outside diameter copper tubing of ordinary wall thickness is satisfactory. In such csase the diameter of the first chamber is about 1 /s4".

The first chamber opens abruptly into a mixing chamber I4. This is cylindrical and coaxial with the first chamber and should be approximately twice as wide as the first chamber, its length `being substantially the same as its width. The mixing chamber is followed by a ared nozzle end l5 into which the inside wall of the mixing chamber runs smoothly. I have found that the flared end is somewhat more efficient from the standpoint of stream or jet distribution if it is somewhat flattened towards its outside end so as to assume an elliptical or oval cross section as shown in Fig. 2.

For eicient breaking up of the stream issuing from the mixing chamber I prefer to employ a novel type of dispersing element. QonVCniently this takes the form of a screw I6 having a flat interior end or dispersing surface I1. The axis of this screw lies in a plane defined by the axis I8 of the jet and the shortest diameter I9 of the elliptical end (see Fig. 2). The flat end of the Screw is at right angles to its axis which in turn makes an angle a (alpha) of about with the axis of the nozzle (see Fig. 1). In other words, the end of the dispersing screw makes an angle (beta of 15 to`25 and preferably20ov with the axis of the nozzle. The jet issuing from the first chamber into the mixing chamber thus impinges on the end of the screw, which has a marked dispersing effect. If the at end projects too deeply into the stream, the break up of the stream will not be optimum. Conversely, if the end does not project deeply enough into the stream break up will not be eicient. The screw may be turned to move its flat dispersing end in or out of the stream to optimum position by means of the adjusting knob 20. The screw is threaded through a boss 2| formed integrally on -the outside of the nozzle.

The side leg I3 is provided with an extension hose 22 through which any suitable iiuid (or dust suspended in uid) may be sucked. For tree spraying with a fungicide or the like a'concentrated solution of the fungicide is placed in a container and sucked therefrom through the exible hose into the aspirator leg and thence into the jet.

For additional break up and the production of extremely ne droplets the mixing chamber is provided with the plurality of peripheral suction ports 23 which slope backwards and outward through the wall of the nozzle, say at an angle of 20. l,

The apparatus of Figs. 1 and 2 may be con-. nected to the end of a hose which in turn is con-. nected to a main of high pressure water. The solution to be mixed with the water is placed in; the container and sucked up into the aspirator. nozzle as described. It is then a simple matter. to direct the issuing jet of mixed solution andwater against a plant, say a tree to be sprayed.; the adjusting screw being turned to `place the; disperser member in position for maximum break up of the stream.

I have discovered that whether themain stream passing through the nozzle is a liquid or` a gas, the proportions indicated above for width and length of the rst chamber apply. The following table gives throat diameters, chamber diameters, and chamber lengths for various sizes of nozzles:v

Permissible tolerance in dimension, =I=5r0%30 From the foregoing permissible tolerance in thedifferencer between throat and chamber cross sec'-` ton it will be seen that' the diameter ofthe first chamber may be from about 4% to about 12.5%"Y grtr than the diameter of the throat andstill obtain the'd'siiidi .feilicieneylfjet throw. Outside. this/range of prpp tions, howeiger efficiency-.drops eifraridlya the Sam" relis vif.f .the,f.chamberlength liesfgo e cit. tenis eich-iii. reet .simon z-shgvrn. iin

:fr Thea apparatus. willie.rv .4 critical :with that fgqnl'figsg. lfand 2V (like parts b. ,ing.-indicatedby:glike fteferencacharactcrs? .sara ait-.1an additicnal iepcis Placed. in the throatimmediatelv :ahead @father Chamber into .which thefaspiratcrrleguenf.

in accordance with Fig. 1 with a throat diameter' of 1%" (at the point where it enters the chamber I2) and with a side leg of about the same diameter, the rst chamber having a diameter of 2%28", will under given water pressure conditions suck in about 1 volume of water from the side leg for each 9 volumes forced through the throat. I f this structure is altered by employing a throat chamber of 1% diameter and 1%" long ahead of the rst chamber, the orice at the rear of the throat chamber being 55" in diameter, the nozzle will suck in 1 volume through the side leg for each 3 volumes in the main stream, pressure conditions remaining equal.

In the light of the foregoing discussion, it will be apparent that the modication illustrated in Fig. 4 should be employed when nozzle range may be subordinated to the suction of increased proportions through the side leg.

The nozzle of Fig. 3 takes the form of a fuel burner. The apparatus is provided with a relatively short cylindrical throat 30 followed by a coaxial cylindrical firstchamber 3| which is about 8% larger in diameter than the throat. The first chamber is followed by a coaxial cylindrical mixing chamber 32 whose diameter is about twice that of the first chamber .and whose length is also about twice the diameter of the rst chamber. As in the case of the tree spraying nozzle, the length of the first chamber is approximately four times the diameter of the throat.

It will be observed that the throat opens .abruptly into the first chamber and that similarly the rst chamber opens abruptly into the second or mixing chamber. Thus the rear end walls of both rst and second chambers should be roughly perpendicular to the axis of the nozzle considered as a whole.

The mixing chamber of the apparatus of Fig. 3 is followed by a flaring or funnel shaped outlet member 33 Iwhich may be directed into a port of a lre box 34.

As in the case of the tree spray apparatus a disperser head 35 is mounted within the mixing chamber. It has a at end which makes an angle chamber .immediately fin iront of :the `:throat through a' metaletubeii or-the 'likewhiehprovides a.:conduitrentering at',right-anglesto the axis Adf; the throat. IThistube -may'be'providedwith. a -valve .-4 I fior-controlling' ythe amount i of *fuel oil or other liquid 1 fuel-.sucked 'the aspirator-or educter.v i Y l, Y The operation olf :the f apparatus of Fig. `3 is simple. High presstire air `is :supplied to -1 the throat yfrom theffeed pipe. The air creates a suction in the first chamber .which draws fuel oil up through the iside leg; The oil and the air are .mixed inA thea mixing vfchianriber:and dispersed by the disperser head,Isomeadditionalair being sucked in through the ring of ports. The mixture is then discharged through the funnel shaped front end into the re box, where it is ignited.

As in the case of the tree spray, the disperser head is moved in' or out of the stream until optimum effect is obtained.

The burner of Fig. 3 operates principally upon the primary air supplied through the throat, the amount of secondary air drawn in being relatively slight. The purpose of the secondary air is, as indicated above, to aid in breaking up the droplets aspirated through the side leg.

Although the expansion between steps, i. e., from the tapered conduit into the throat chamber (in the case of the apparatus of Fig. 4) and from the throat into the rst chamber and from latter into the mixing chamber in the case of the other forms of the apparatus, should be as abrupt as possible, the rear Wall of the Several chambers need not make precisely a right angle with the main axis of the apparatus. A slight forward slope, say 20% of this end wall away from the axis may be tolerated, hence the chambers may be drilled with a drill having a rather flat conical point.

As indicated previously, the apparatus of the invention is rugged, efficient and relatively `cheap to manufacture. It may be used for aspirating both liquids and gases, and even dust, if suflciently free and unpacked, may be aspirated through the side leg.

I claim:

1. In an aspirating nozzle, the combination which comprises a throat portion of relatively small cross-section, a rst enlarged chamber into which the throat opens abruptly, the first enlarged chamber being concentric with the throat portion and cylindrical in shape, the diameter of the rst chamber being from 4.0% to 12.5% greater than the smallest diameter of the throat portion and the length of the first chamber being from 2.8 to 5.2` times its diameter, an aspirating conduit connected to .the rst chamber, a second enlarged cylindrical chamber downstream from the rst chamber and concentric therewith but of still greater cross section. the first chamber pinges on said fiat end.

opening abruptly into the second largerchamber, and a disperser member having a at end, said fiat end being disposed in the second enlarged chamber at an angle of 15 to 20 with the axis of the nozzle and of a stream which im- 2. Apparatus according to claim 1 provided with means for moving the flat end of the disperser member into and out of the stream While maintaining Said angularity with respect to said stream.

3. Apparatus according to claim 1 in which the disperser member comprises a screw threaded into the Wall of the second enlarged chamber.

4. In an aspirating nozzle having a front chamber from which a stream is ejected, the combination which comprises a disperser member having a flat surface set in the chamber at an angle of 15 to 25 with the axis of the nozzle and the stream Which impinges on said at surface, and means for moving this member toward and away from this axis without changing the angle Which said iiat surface makes with the axis.

LOUIS T. HERRMANN.

REFERENCES CITED 8 UNTI'ED `STATES PATENTS Number Number Name Datey Caswell Aug. 18, 1891 Thiesen Dec. 3, 1895 Harris May 14, 1907 Lawton Aug. 4, 1914 Motsinger Mar. 30, 1915 Philibert May 30, 1916- Sullivan Apr. 15, 1924 Kreiziger Dec. 8, 1925 Mulroy Apr. 13, 1926 Herold Jan. 11, 1927 Heinrich May 6, 1930 Nelson Jan. 13, 1931 Parker Feb. 4, 1936 Timpson Oct. 13, 1936 Davis Nov. 10, 1936 Mowery June 14, 1938 Twombly Apr. 2, 1940 Parker Sept. 17, 1940 Lindstaedt Aug. 4, 1942 Tirrell Feb. 13, l1945 Phillips May 20, 1947 FOREIGN PATENTS v Country Date Great Britain May 5,` 1930 France Nov. 27, 1924 

